2015 GMC Yukon Denali Gains 8L90 Eight-Speed Automatic Transmission

General Motors confirmed at last that its GMC-badged full-size SUVs are going to receive the newest member of the Hydra-Matic family. Designed to be more fuel-efficient than the six-speed slushbox of yesteryear, highway mileage estimates for the two-wheel drive Yukon Denali and Yukon XL Denali increase to 22 mpg with the 8L90 transmission.

As for the four four-wheel drive models, fuel economy rises to 15 mpg highway. According to the American manufacturer's estimates, the 2015 GMC Yukon Denali delivers highway fuel economy equal to or better than the V6 or V8 engines of segment rivals such as the Infiniti QX80 and Toyota Sequoia.

The 6.2 EcoTec V8 is rated 420 horsepower and a hefty 460 lb-ft (623 Nm) of torque

Compared to the previous six-speed transmission, the 8L90 offers smaller steps between gears for better leverage of the peak power band. Wider gearing spread also allows the use of a lower 3.23:1 rear axle ratio, reducing engine speeds and fuel consumption. As for tow ratings, the 2015 GMC Yukon Denali boasts with 8,400 pounds, while the 2015 GMC Yukon XL Denali can tow up to 8,100 pounds.

Last but not least, the updated GMC full-size SUV also adds a hands-free power liftgate, smartphone wireless charging a la the 2015 Cadillac ATS and the OnStar 4G LTE with Wi-Fi hotspot system. In addition to those, there’s an enhanced GMC Intellilink infotainment system with Text Message Alerts.